Building toy



Feb. 14, 1967 R. G. MOTE BUILDING TOY Filed Feb. 10, 1964 INVENTOR.19055876. M075 BY 9,], H. W

United States Patent 3,303,604 BUILDING TOY Robert G. Mote, 1132 QueensAve., Yuba. City, Calif. 95991 Filed Feb. 10, 1964, Ser. No. 343,721Claims. (Cl. 46-25) This invention relates to a building toy for youngchildren comprised of structural units which interfit together innumerous and varied Ways. More particularly, the invention relates tosuch a toy in which the structural units are preferably made from emptymilk cartons of the waxed cardboard variety.

It is common knowledge that small children, particularly those in theage group from about 2 to about 8 years, derive much useful benefit frombuilding toys made up of structural units which can be variouslyassembled or interfitted together to form simulated buildings or otherstructures. In addition to directly benefitting the children by helpingto develop and improve their mental and manual skills, such toysindirectly benefit their parents and others charged with theresponsibility of raising or caring for the-m by helping to keep theyoungsters occupied and out of mischief for substantial periods of time.

Much of the milk sold at retail is dispensed in waxed cardboardcontainers (hereinafter, for the sake of brevity, referred to as milkcartons or simply cartons), typical of which are the 1- and Z-quartmil-k cartons commonly seen in supermarkets and other grocery stores.These cartons are presently classified and treated by seller and buyeralike as throwaway containers of the same category a's empty tin cans,beer bottles, etc. I have now discovered a meansof converting suchcartons into structural units suitable for the building toy purposes ofthis invention. The advantages of this are two-fold; namely (1) theconversion of a heretofore useless discard product into a useful item,and (2) the provision of a new and useful-toy. V

It is thus a principal object of this invention to furnish a new anduseful building toy.

It is a more specific object of the invention to furnish a means ofconverting used milk cartons, presently substantially worthless discarditems, into useful toy products.

Other objects, features, and advantages of the present invention willbecome apparent as the description thereof proceeds.

My toy structural units can be made in various ways, one such being thecutting of milk cartons to appropriate shapes as taught herein andillustrated in the accompanying drawings. carton or other origin, arecharacterized by cooperatively mating features permitting them to beassembled into structures of a great variety of sizes and shapes.

The structural units, whether of milk' The choice of structural varietythereby afforded is virtua-lly without limit, except for such inherentlimitations as are imposed by the shapes of the structural unitsthemselves. This feature of the invention permits the child to give fullrein to his imagination and contributes substantially, it is believed,tothe utility of the invention. The substance and scope of the presentinvention will be better understood by reference to the accompanyingdrawings, of which:

FIGURE 1 is a perspective view of a possible assembly of structuralunits exemplary of the units of this invention;

FIGURE 2 is a view of the assembly, mostly in section, taken along line2-2 of FIGURE 1;

FIGURE 3 is a fragmentary sectional view of the assembly taken alongline 3--3 of FIGURE 1;

FIGURE 4 is a perspective view, with hidden-line delineation of certainfeatures not otherwise visible, of a structural unit in accordance withthis invention;

end flap means for interlocking connection with another unit havingcooperating end flap means.

A detailed description of the drawings follows, throughout which thepictured embodiments of the structural units are described in languageconsistent with milk carton origin of the units. This technique is, itis believed, conducive to a better understanding of the design geometryof the involved parts, but it should not be inferred from its use thatmy structural units are necessarily of milk carton origin, since, aspreviously indicated, they can be prepared from any suitable sourcemate-rial. The important criteria are the shapes and relative sizes ofthe units, not their :genetic histories. There are, however, somepreferences as to choice of materials of construction, and these will bediscussed in greater detail hereinafter.

Turning now to a consideration of the drawings, it is first pointed outthat all of the structural units depicted are of square cross-sectionand equal cross-sectional area. It is not essential, however, that thecross-sectional areas of the units be equal, and they can vary in thisrespect if desired. For example, it is within the functional realm ofthe invention to form assemblies of structural units configured astaught herein, but sized consistently with both quart and half-gallon,or other capacity, milk carton derivation.

For the most part, as the drawings show, my toy structural units fit,and are held, together to form the various assemblies of the inventionat a plurality of points by male and female coupling means. The couplingmeans comprise snugly interfitting male members and receptive femalemembers so disposed as to permit connective relationship between theunits in fulfillment of the purposes of the invention. The definitivegeometry of the cooperating male and female parts of my structural unitsis unique in my experience, and permits connective assembly of the unitsin a way hitherto unknown insofar as I am aware.

The male and female features of my structural units are each reducibleto one of three-basic forms, here considered, for the previouslydisoused reasons, in a context assumptive of derivative mutilation ofmilk cartons. In this connection, the preferred milk cartons forconversion to structural units in accordance with the teachings hereinare those of the conventional rectangular parallelepiped shape, and, toresort to redundancy for the sake of emphasis, having fiat ends.However, as will eventually be apparent, milk cartons of other shapes,(so long as they have square cross-sections) are equally applicable forthe indicated purpose, exemplary of such cartons being those with gabledpouring ends of the type familiarto all.

While, as will by now be more than evident, a preferred way of making mynovel building units is by carving them out of empty milk cartons, it iswithin the spirit and scope of the invention to manufacture the unitsdirectly from appropriate starting materials, or otherwise make orcontrive them. There is nothing critical about the materials ofconstruction for the units aside from the obvious necessities occurringto one familiar with the invention. Some suitable materials will,because of certain properties, be preferred over other equally suitableones, but in general almost any solid material will suflicea Preferredmaterials, other than the aforesaid waxed cardboard, are plastics, hardrubbers, wood, thin plate metals, etc.

Proceeding now to the specifics of the male and female coupling featuresof my toy building units, the three configurational variants aboveadverted to are: (l) a transverse notch cut through the milk carton, twoexamples of which are shown at 1 and 3 on the FIGURE 4 unit, hereinafterreferred to simply as the notch cut; (2) a transverse notch cut in twodihedral side walls of a milk carton, as shown at 5 on FIGURE 7,hereinafter referred to as the single side-notch cut, and; (3) a hole.in one side wall of a milk carton, equal in shape and size to half ofthe wall opening of a single side-notch out (such a hole being shown at7 in FIGURE 6), hereinafter referred to as the half-notch cut.

The notch cut is V-shaped in profile, sloping inwardly from points on aline passing perpendicularly through the longitudinal axis and twodiagonal corners of .a milk carton to dihedral intersection at theoppositely diagonal corners of the carton. The dihedral points of thenotch cut on said oppositely diagonal corners of the milk carton fall ona line perpendicular to the longitudinal axis of the carton, and theangle of intersection of the sloping planes delineative of said notchcut intersect at an angle of 90. This angle permits straddling interfitbetween the notch cut of one unit and a dihedral corner of another unit,as well as mating relationships with units having single side-notch andhalf-notch cuts, as will presently be explained. The notch cut resultsin the formation of two ears of right triangular pyramidal shapeprojecting outwardly from the valley of the cut and terminating inapices disposed at opposite diagonal corners of the carton, as shown at9 and 11 on FIGURE 4. It will, of course, be apparent that only two ofthe pyramidal walls of each ear are real, the third one, in eachinstance, being merely an imaginary planar surface coexistent with thesloping lines of the cut in the appropriately situated walls of the milkcarton.

This is not to say that ears having all finite walls, or even completelysolid ears, are without the scope of this invention, since, as will beseen, all suoh are clearly within its functional capabilities.

The single side-notch cut is of a V-shaped profile, extending half-waythrough a milk carton in the transverse direction, with the open end ofthe V disposed along a first dihedral corner thereof, and the closed endof the V coexistent With a line perpendicularly disposed with respect tothe axis of the carton, and joining the two dihedral corners nearestsaid first dihedral corner of said carton. The V-shape of the singleside-notch out has a channel angle of 90, thereby permitting astructural unit with such a cut to snugly cradle a second structuralunit in perpendicularly transverse relationship thereto, with thedihedral corner of the latter in mating repose within the channel grooveof said out. In addition to permitting the described cradlingrelationship, the single side-notch cut is of precisely the right sizeto snugly receive the notch-cut end of a structural unit so defined.When making the suggested insertion, the tips of the ears of thenotch-cut .of the latter or male unit should be so oriented as to enterthe single side-notch cut of the other, or female, unit at its widest,as seen in profile, end. When the ears of the male unit thus orientedare pushed through the side-notch cut opening in the female unit totheir fullest extent, they abut,

the inner walls of the latter in matingly cooperative rela- 17 and 19,with single side-notch cuts respectively, in the above-described manner,and FIGURE 3 illustrates the I resulting mating interfit between theears of male unit 15 and the inner walls of female unit 19.

The male and female structural features making it possible to couple myunits together in the above-indicated way are preferably so sized as toassure a relatively tight cult for small children to put the unitstogether and take fit therebetween, although not so tight .as to make itdiffiwalls penetrated by the latter.

them apart again. Structural units with optimum male and femaletolerances are made with relatively little difficulty from hollowstarting materials such as empty milk cartons. It is again emphasized,however, that my toy structural units can be made from materials otherthan empty milk cartons or the like. It is even within the scope of theinvention to provide such units of solid, rather than hollow,construction, except for the necessary openings and internal hollows ofthe proper sizes and shapes to satisfy the requirements taught herein.It is also within the scope of the invention to utilize structural unitsof mixed hollow and solid construction, so long as they are designed tointerfit in a manner, and thus perform functions in accordance with thisinvention.

It is not essential that the subject male and female parts be as closelytolerant as their preferred status requires, and they may fit looselywithin the bounds of the invention since many structural assemblies arestill thereby achievable.

The half-notch cut, as previously indicated, and as the name implies, isthe equivalent of half of a single sidenotch cut occurring in either oneof the dihedral carton This manner of description is employed as atechnique to more easily and quickly paint a verbal picture of thevisual interrelation of the two involved types of cut, and hence, it ishoped, promote faster and keener sensual appreciation thereof. Infunctional reality, however, the half-notch cut is entirely differentfrom, rather than merely a fractional part of, the single side-notchcut, as will soon become apparent. The primary function of a half-notchcut is to serve as a receptive opening for one of the ears of astructural unit with a notch cut, and thereby provide another means ofcoupling my units together.

To couple a unit with a notch cut to one with a halfnotch cut, one earof the former is inserted into the halfnotch cut of the latter as far asit will go to an angle of about 45, as measured between the axis of thecarton with the notch cut (male unit) and the plane of the wall of theother carton (female unit) dihedral with the wall pierced by thehalf-notch cut and adjacent the wide end of said cut. When the male unitis thus partially inserted into the female unit, a symmetrical portionof the former, including one ear and anintegrally adjacent segment inthe mirror image shape of said ear, is engulfed in the cavityof thelatter. The fully inserted ear of the male unit bears flatly, around itsnotch-cut edges, against the inner surface of the wall of the'femaleunit previously identified as that dihedral with the wall penetrated bythe half-notch cut and adjacent the wide end of said cut, and thedihedral corner of the male unit extending from the tip of its insertedear is snugly cradled in the V-shaped peripheral edges of the half-notchcut converging from its wide end. The tip of the inserted ear extendsinside the female unit approximately to the line of intersection betweenthe wall against which said ear bears and the wall opposite and parallelto that penetrated by the half-notch cut.

The described interfitting relationship will be better understood byreference to the drawings, which show, in FIGURE 6, the wide end 21 of ahalf-notch cut in a female unit and a wall 23 of'such a unit against theinner surface of which the ear of a male unit bears when the two unitsare coupled in the manner here taught. The drawings further show, inFIGURES 1 and 2, an. eared male unit 25, inserted to the fullest extentin a female unit 27, FIG- URE 2 revealing, at 29, the abuttingrelationship between the ear of the former and the appropriatelyadjacent inner wall of the latter.

In addition to the interfitting features of my structural units so fardescribed, there is an additional one within the compass of theinvention, this being an interlocking means for holding the unitstogether in end-to-end relationship. Basieally, the interlocking meanscomprises two or more, but preferably two, pairs of cooperatingsemi-circular flaps, each pair representing two units and each flapbeing sprung outwardly to a sufficient extent (but only to such anextent) to permit insertion of its cooperating counterpart flapthereunder. It will be apparent that here, as in the case of the otherinterlinking features of this invention, any number of structural unitcombinations can be adapted to interlock in the prescribed manner, therebeing nothing critical about the number of pairs of such interlockingunits. Also, and this is equally applicable to all pairing orinterlinking variants taught herein, there can be any possible numberand variety of other interfitting or coupling features present onstructural units incorporative of the presently-described fasteningflaps. It is sufficient, for purposes of this invention, if some of theinvolved structural units have at least some of the mating male andfemale features taught herein, and it is immaterial how and to whatextent those features are distributed or scrambled on the individualunits themselves. For example, a structural unit can be of wholly malecharacter, such as that of FIGURE 4 (notch-cut on both ends) or FIG- URE5 (notch-cut on one end only); of wholly female character, such as thoseshown in FIGURES 6 and 7, or units having two or three single side-notchcuts each; or of hermaphroditic character, having both male and femalefeatures.

Turning again to the subject of the end-to-end fastening means for thestructural units, the preferred spacing arrangement for the involvedsemi-circular flaps is one of symmetry along a diagonal of the squareunit end, with each flap describing an arc segment of the same radiusaround a center located on the diagonal. Two flaps, such as described,are shown at 31 and 33 on FIGURE 7. It will be observed that the flapsextend in mutually opposite directions from the diagonal on which theirare centers are located, the reason for which will be apparent from anunderstanding of the manner in which they cooperate with flaps on otherunits to perform their interlocking function. To interlock two units inaccordance with present teachings, their ends are placed flatly togetherwith their flaps so positioned as to each ride under a complementaryflap on the stranger unit when said units are twisted in appropriatelyopposite directions, and then so twisting said units untl each flaprotates under the uncut portion of the circle of its cooperating flap onthe stranger unit. At the completion of the twisting motion, the twostructural units are joined endwise in substantially perfect alignment,and are presented from relative longitudinal movement by the underlap ofeach of its flaps with the uncut portion of the circle of a counterpartflap on the other unit. To unlock the two units, they are simply twisteduntil the flap fastenings disengage.

It should be emphasized that the number and pattern of disposition ofthe aforesaid flaps on my structural units, and even the shape of theflaps, can vary in numerous ways within the scope of this invention.However, the flap pattern and other related particulars should besubstantially the same on all units intended for mutualy reciprocal endengagement if proper interlocking of the units is to be achieved.Thus,'for example, corresponding flaps on separate units must extend inthe same relative directions from their are centers, rather than inopposite directions, as will be demonstrably evident from any attempt toengage two units with oppositely extending flaps. Finally, as FIGURES 2and 7 illustrate, the flaps on opposite sides of the center of anycommon line therethrough (typically a diagonal of the square end of astructural unit) extend in opposite directions, respectively, from saidline. The reason for this will be apparent from an understanding of themanner in which the subject interlocking means functions.

An optional feature of my invention is the provision of intermediatelongitudinal slots, which may be wholly or partially V-shaped, in thesloping end edges of theear walls of notch-cut units, as illustrated byFIGURE 5. The

purpose of such slots is to increase the interlinking versatility of theinvolved notch-cuts. Various other modifications of a similar characterwhich contribute to greater functional adaptability of the structuralunits without countervailing their basic character or integrity are alsooptional and within the contemplated bounds of my invention.

FIGURE 1 shows one of the many possible assemblies, or aggregativestructures, which can be built from the structural units of thisinvention. While the FIGURE 1 structure is of relatively uncomplicatedcharacter by comparison with any of the almost infinite number ofsubstantially more complex structures possible of achievement with mystructural units, it is felt to be sufiiciently inclusive of the variousinterfitting and interlinking means encompassed by the present inventionto comprehensively teach the fundamentals requisite thereto.

Considering FIGURE 1 now in greater detail, the lowermost support memberof the pictured structure is a vertically disposed unit 34 having a flatbase which rests upon a supporting surface (not shown) and a notch cutdefining the shape of its upper end. Unit 35 supports the two previouslymentioned female units 17 and 19 in transverse cradling relationship asshown, said units being joined end to end by flap fastening means suchas those formerly described and illustrated at 31 and33 on FIGURE 7.Female units 17 and 19 in turn support two male units 13 and 15, whichare inserted respectively therein in the manner shown and previouslydescribed in detail. From FIG- URE 1, considered in conjunction withFIGURES 2 and 3 and the foregoing descriptive material, the interfittingrelationship and orientation of each unit relative to pertinent othersis clear. In this connection, it will, of course, be evident thatinterconnected units 13, 15, 17 and 19 are, of necessity, supported byunit 35 at their midpoint of symmetry, which occurs at the plane ofend-to-end interlock of units 17 and 19. The necessity for thismidpoints support, occasioned by the obvious need for balance in thestructure, demonstrates one child training factor inherent in mybuilding toy, this being a requirement for sound design judgment ifsuccessful completion of a self-supporting structure to be achieved, andthe consequent improvement in the abilities requisite to such designjudgment (as well as design skills in general) which continuous use ofthe toy engenders.

Disposed in direct vertical alignment above unit 35, is another unit 37having a notch-cut figuration at each end and being similar inappearance to the FIGURE 4 unit. The notch cut in the lower end of unit37 straddles the midpoint of end-to-end joined units 17 and 19 in suchfashion that the tips of its defining ears meet the upwardly extendingtips of the ears on unit 35. Cradled in the upper notch cut of unit 37is a female unit 27, of previous discussion, with a half-notch cut inits forwardly facing upper side. The two notch cuts in unit 37 arediagonally corresponding (so that both are simultaneously silhouettedagainst a common planar background) and female unit 27 reposes in theupper notch cut in parallelism to the co-extensive axes of end-connectedunits 17 and 19. Partially inserted within the half-notch cut in unit 27is a male unit 25 marking the peak of the structure.

I have fashioned a number of my structural units from empty milk cartonsand have made numerous structures having shapes suggestive of animals,robots, etc., therefrom, as well as many aggregative assembliessuggestive of nothing in particular, but requiring imagination, skilland patience to complete without mishap. More importantly, I havepermitted young children, my own as well as others, to play with themilk carton units, as a result of which I noticed that they remainedpreoccupied for relatively long periods of time, assembling andreassembling the units into structural combinations of numerous andvaried shapes and sizes.

Four configurational features of my structural units all four of themfor its existence.

-cntrib'utive to interfitting or interlocking relationship therebetween,namely, the notch cut, the single side notchcut, the half-notch cut andthe end flap fastening means, have been described in detail hereinabove.While each of these features makes a significant contribution to thesubstance of my invention, I wish to make it clear that the inventiondoes not depend upon the concurrency of Thus, the absence of one or moreof the features from a set of. structural units otherwise within thedefinitive limits of the invention does not necessarily render the setinoperative to the point of non-includability within those limits. Thisdoes not mean, however, that any combination of two or more of the fourfeatures in a set of structural units is a ticket to such includabilityof that set. Thus, there are certain combinations of features so barrenof potential productivity as to yield nothing of patentable merit, suchas, for example, those found in sets of wholly female structural unitscharacterized only by single sidenotch and half-notch cuts. In contrast,there are other combinations of features of relatively high potentialproductivity, such as sets of structural units incorporative of bothmale and female features in such number and manner of distribution as toassure many aggregations of interfitting parts.

As will by now be apparent, the number of possible combinations ofstructural units of the various types taught herein is legion, of whichthose combinations within the scope of this invention are likewiselegion. Whether or not a combination is within the latter categorydepends upon a number of factors, including the number of unitsinvolved, the number of types of interfitting or interlocking featurespresent,.the manner of distribution of said features on and among theunits, and so on. Accordingly, it is difficult to draw a narrowborderline between those unit combinations blessed with the mantle ofinventive respectability and those'not so blessed. Suffice it to say,that the minimal requirement for the includability in the former groupisbelieved to be the presence of the 'male configurational feature(notch cut) and at least one of the female features (single side-notchor half-notch cut) on separate units,

'whereby said units could be made to 'interfit .in accordance withpresent teachings. Preferably, there should be a plurality of more thantwo of the oppositely sexed units present, but one of each is feltsuflicient to bring a set of my structural units within the purview ofthis invention.

Because of their unusual shapes,the structural units of this inventionare impossible of accurate characterization in concise terms.Consequently, shorthand terminology of an ambiguous character standingalone but clear import in context has, for the sake of brevity, beenemployed in the foregoing description of the-units, the distinguishingstructural features of the units, for example, thereof being referred toas notch cuts, single side-notch cuts, half-notch cuts and end flapfastening means, respectively (the term distinguishing being presentlyemployed in no sense inconsistent with anything previously taughtherein). By means of this shorthand technique, a simplified disclosureof the geometrical intricacies of my building toy units, completelysatisfactory for patent specification purposes, was made possible.

For claim recitation purposes, however, the technique leaves somethingto be desired, and the aforesaid features of the structural units willtherefore be identified in terms of structural detail, rather thanshorthand terminology, in the claims to follow.

Another semantic peculiarity of the foregoing description of my buildingtoy, not unlike that just discussed,

is the absence of a descriptively generic term for the basic toy unitsthemselves, by which is meant the units without their distinguishingfeatures. Such an absence was there felt justifiable since, as will berecalled, the building ,31 35 d$flibd in terms of milk cartonderivation, rather than geometric shape, of its structural units,

the former approach being considered a simpler and easier way ofteaching the basic unit shapes than the latter one. As in the case ofthe distinguishing features of the building toy units, and forsubstantially the reason there applying, the toys basic units will behereinafter claimed in language of a more definitive character than wasused in the aforesaid description.

7 Going now from the general to the specific, the basic units of mybuilding toy will be hereinafter described in the claims as tubes whichare square in cross section, the term tubes, as presently contemplated,being intended to encompass tubular members of nonelongate form, as wellas such members enclosed at one or both ends. The toy unit featureheretofore referred to as a ,notch cut will be claimed as a notchdefined by end surfaces lying entirely in two planes, said two planesintersecting each other at a right angle, the line of intersection ofsaid two planes being in a first axial plane containing two diametralcorners of the tube of notch incidence and being perpendicular to asecond axial plane containing theother two diametral corners of saidtube, said first axial plane bisecting said right angle, whereby twomale tube segments symmetrical about said first axial plane are formed.

Those structural unit features heretofore referred to as singleside-notch and half-notch cuts, respectively, will be semanticallyconsidered, for claim recitation purposes, as mating female notches forboth and one, respectively,

of the male tube segments defining a notch cut, said female' notchesbeing each so positionally oriented as to receive its mating malemembers, or member, as the case might be, with the axis of itsstructural unit of incidence in perpendicular relationship to that ofthe structural unit of incidence of said male members, or member. Thesingle side notch and half-notch cuts will accordingly be. claimed inlanguage essentially equivalent coated cartons, as well.

in language of appropriately descriptive character, ade-' .quate supportfor this can, itis believed, be found in the earlier description of theunits without the need of further elaboration here.

While it hardly seems necessary so to do, it is pointed out that theterm milk carton as employed in broad concept in the foregoingdescription, as well as in the appended claims, is connotative ofstructural configuration and construction materials consistent with milkcartons, and not function. In other words, by milk cartons, is meantcartons of the type used as milk containers regardless of their actualuse (which may be for containing orange juice, fruit punch, etc.).Additionally, while the milk cartons of this invention have beenpreviously identified as being of the waxed cardboard variety, thatlanguagewas used for convenience only and was never intended to beconstrued in a literal or limitative sense. Thus, the term milk cartonsas employed above and in the claims following hereinafter includes notonly those of the waxed cardboard variety but equivalent ones, such asthe more recently employed plastic- In fact, the latter containers areperhaps superior to the older-waxed cartons for purposes of myinvention.

Finally, to avoid possible misunderstanding from the tenor of the abovedescription, I wish to emphasize that I do not necessarily prefer themilk carton embodiments of this invention over other embodimentsthereof. In this connection, as a matter of fact, it is my feeling thatthe preferred, and more logical applicability of the invention residesin the manufacture of the structural units of my building toy fromsuitable plastic materials, preferably of multi-colored design. As Ihave previously tried to make clear, the emphasis on milk cart-onderivation of the parts of my toy in the foregoing disclosure wasintended purely as a device to simplify the description of the oddlyshaped parts and not as an indication of limitability of the inventionto such derivation.

It will be apparent from the above that numerous modifications of thedescribed building toy are possible. All of these are within the purviewof my invention provided they fall within the scope of the followingclaims.

I claim:

1. A building toy comprising a plurality of structural unitscharacterized by at least two features which make mating interfitbetween said units and consequent assembly thereof into aggregatespossible, said features being so distributed as to permit suchunitinterfit and aggregative assembly;

(a) said structural units being tubes which are square in cross-section;

(b) at least one of said features being a notch in at least one of saidtubes, said notch being defined by end surfaces of walls of said onetube, said end surfaces lying entirely in two planes, said two planesintersecting each other at a right angle, the line of intersection ofsaid two planes being in a first axial plane containing two diametralcorners of said one tube and being perpendicular to a second axial planecontaining the other two diametral corners of said one tube, said firstaxial plane bisecting said right angle, whereby two male tube segmentssymmetrical about said first axial plane are formed;

(c) and at least one other of said features being means in the form of afemale notch in at least one other of said tubes for mating with atleast one of said two male tube segments, each such female notch beingso positionally oriented on its respective structural unit as to permitmating engagement of its unit with, and in axially perpendicularrelationship to, another of said structural units having a notch asdefined in sub-paragraph (b).

2. The building toy of claim 1 in which the features 4 which make matinginterfit between said units and consequent assembly thereof intoaggregates possible comprise a plurality of said notches of the maletube segment forming type described in sub-paragraph (b) and a pluralityof said means in the form of mating female notches, as described insub-paragraph (c), for the male tube segments, at least one of saidfemale notches being receptiveof one of said tube segments and at leastone being receptive of a pair of said tube segments symmetrical about acommon structural unit tube axial plane.

3. The building toy of claim 1 in which at least one of the structuralunit tubes of sub-paragraph (a) has at least one end enclosed.

4. The building toy of claim 1 in which at least one end on each of twoof the structural unit tubes of subparagraph (a) is enclosed by a fiatenclosure disposed perpendicularly to the axis of its structural unit ofincidence, said flat end closure being characterized by end fiapfastening means adapted to engage similar means on an end enclosure ofsimilar character on a separate structural unit tube when the twoend-flap-fasteningmeans-distinguished unit tubes are twisted inend-abutting relationship and in proper positional and twist-directionalorientation to effectuate the engagement, whereby said structural unittubes are thereafter securely held in connectively aligned andend-to-end relationship,

5. A building toy in accordance with claim 1, characterized in that atleast one notch defining tube wall portion of at least one of the maletube segments formed by a notch as defined in sub-paragraph (b) has ashallow cut running from its edge for a distance less than the depth ofthe aforesaid notch, said cut also running substantially parallely tothe axis of the structural unit tube of its incidence.

References Cited by the Examiner UNITED STATES PATENTS 2,147,237 2/ 1939Bluthardt 4625 2,425,729 8/ 1947 Sherbinin 4625 2,440,836 5/ 1948Turngren 4625 2,446,179 8/1948 Harnquist 4625 2,805,516 9/1957 Palm46--11 3,009,283 11/1961 Gogina 4611 X 5 RICHARD C. PINKHAM, PrimaryExaminer.

F. BARRY SHAY, Assistant Examiner.

1. A BUILDING TOY COMPRISING A PLURALITY OF STRUCTURAL UNITSCHARACTERIZED BY AT LEAST TWO FEATURES WHICH MAKE MATING INTERFITBETWEEN SAID UNITS AND CONSEQUENT ASSEMBLY THEREOF INTO AGGREGATESPOSSIBLE, SAID FEATURES BEING SO DISTRIBUTED AS TO PERMIT SUCH UNITINTERFIT AND AGGREGATIVE ASSEMBLY; (A) SAID STRUCTURAL UNITS BEING TUBESWHICH ARE SQUARE IN CROSS-SECTION; (B) AT LEAST ONE OF SAID FEATURESBEING NOTCH IN AT LEAST ONE OF SAID TUBES, SAID NOTCH BEING DEFINED BYEND SURFACES OF WALLS OF SAID ONE TUBE, SAID END SURFACES LYING ENTIRELYIN TWO PLANES, SAID TWO PLANES INTERSECTING EACH OTHER AT A RIGHT ANGLE,THE LINE OF INTERSECTION OF SAID TWO PLANES BEING IN A FIRST AXIAL PLANECONTAINING TWO DIAMETRAL CORNERS OF SAID ONE TUBE AND BEINGPERPENDICULAR TO A SECOND AXIAL PLANE CONTAINING THE OTHER TWO DIAMETRALCORNERS OF SAID ONE TUBE, SAID FIRST AXIAL PLANE BISECTING SAID RIGHTANGLE, WHEREBY TWO MALE TUBE SEGMENTS SYMMETRICAL ABOUT SAID FIRST AXIALPLANE ARE FORMED; IN THE FORM OF A FEMALE NOTCH IN AT LEAST ONE OTHER OFSAID TUBES FOR MATING WITH AT LEAST ONE OF SAID TWO MALE TUBE SEGMENTS,EACH SUCH FEMALE NOTCH BEING SO POSITIONALLY ORIENTED ON ITS RESPECTIVESTRUCTURAL UNIT AS TO PERMIT MATING ENGAGEMENT OF ITS UNIT WITH, AND INAXIALLY PERPENDICULAR RELATIONSHIP TO, ANOTHER OF SAID STRUCTURAL UNITSHAVING A NOTCH AS DEFINED IN SUB-PARAGRAPH (B).